Should we be worried that foreign companies are buying up large swathes of British industry? The answer is a resounding no. In fact, we should be glad that so much capital is pouring into the country, securing jobs and factories and providing new owners with a platform for more investment.

Take the example of Marconi, which is selling much of its electronics business to Ericsson of Sweden. Marconi is a shadow of its former self following a series of ill-starred acquisitions by its previous British management - without Ericsson's takeover, it is doubtful that Marconi could survive as an independent company.

Marconi is a minnow in a world of giants and it lacks scale, so bring on the Swedes - you won't hear any protests from the once-anxious employees.

All right, there is some evidence that during an economic downturn foreign companies tend to cut back abroad rather than in their domestic markets. And Britain's light regulatory climate makes it an easier target for cuts than, say, France, where firing workers can attract punitive taxes and the attention of the courts.

But the flip side is that when companies from abroad are flush with cash and the economic climate is relatively benign, Britain's open and dynamic market makes our country a magnet for foreign capital.

We may not have a car industry, but thousands of workers are employed by Nissan, Honda, Peugeot, Ford and Fiat: all companies attracted by Britain's receptive and business-friendly environment.

Some describe the scenario as Wimbledonisation: we may not have the best tennis players anymore, but Wimbledon is where the champions most want to play. So it is with UK plc; some of the world's best-known multinationals want to come here because there is less red tape and taxes are lower than in France, Germany, Belgium or Holland. And unlike the Americans, we are less inclined to throw up 'strategic' reasons why Chinese companies should be locked out, as many US politicians argued when Beijing-based oil company CNOOC tried to take over American rival Unocal earlier this year.

Quite simply, Britain is probably the most open market in the world; perhaps this should come as no surprise: we are, after all, one of the oldest trading nations, and we know the benefits and wealth that can flow from free, unfettered trade. Not for Britain the economic nationalism of France, which is putting up barriers to foreign investment in industries as far flung as casinos and cryptology, although the evidence suggests that the French are shooting themselves in the foot as France, like any other country, could benefit from an infusion of outside talent and ideas.

And the advantages for Britain are clear: according to government figures, the number of jobs created by overseas companies in the UK last year stood at more than 39,000, catapulting Britain to the top of the league table for foreign direct investment.

In total, the value of foreign investment quadrupled in 2004, with Britain gaining largely at the expense of France and Germany, and despite being outside the eurozone.

But how foreign are the foreign raiders queueing up for a slice of corporate Britain? Not as foreign as you might expect if you look at their ultimate owners - many have the same big institutional investors as British companies: Deutsche Asset Management, Fidelity, Société Générale, Nikko and New Star, which hold stakes in companies across the world. And don't forget that more than 20 per cent of the British stock market is held by overseas shareholders.

Having an open market brings immense benefits for customers in that there is more choice on offer, and from leading global players. And more competition for services and products usually means value for money and higher standards than where markets are protected.

The TUC's chief economist Ian Brinkley argues that foreign deals are often better for British employees because overseas companies, especially the Japanese, often invest more per worker than their UK counterparts.

Because there have been so many foreign acquisitions in the last 10 months - worth £70 billion, nearly twice the value than of the whole of 2004 - it is easy to jump to the conclusion that the traffic is all one way, but not so. Over the last 10 years, foreign companies have acquired assets here valued at £250bn, but UK firms have made acquisitions abroad worth double that figure at £500bn, BP's purchase of Amoco and Vodafone's acquisition of Mannesmann being among the biggest.

Of course, not all foreign takeovers of British firms will be good news, but if they fail, it will be because they makes the same mistakes as UK companies, overstretching themselves or falling victim to sloppy management.